Free Space Optical(FSO) Communication Link Design Under Adverse Weather Condition

This paper presents the link budget calculations for Free Space Optical (FSO) communication system under adverse weather conditions. For free space optical communication, atmospheric losses are the dominating factors in the link budget analysis. This paper discusses various factors which influence the medium between the transmitter and receiver and the link budget calculations. Transmission power is the main priority in link budget, which decreases gradually along the path due to attenuation effects caused by weather conditions. Theoretically, more transmission power is received at the receiver when scattering is low due to low level of attenuation, Total losses should be catered in such a way that sufficient power is available at the receiver to retrieve the information. In this paper performance of 1 Km FSO link with 10 Mbps data rate is calculated in terms of Signal to Noise Ratio (SNR) and Bit error Rate (BER) for different kinds of modulation scheme in different atmospheric conditions such as rain, fog, snow and temperature gradient etc.